Mole Day is celebrated annually on October 23 from 6:02 a.m. to 6:02 p.m., and commemorates Avogadro's Number (6.02 x 10²³), which is a basic measuring unit in chemistry.   The Mole Day Festivities included a chemistry-themed cake, guacamole, molasses cookies, and beverages.  
Did you know that a one liter bottle of water contains 55.5 moles of water?